OPTIONAL FEATURES
HeatNet Control V3
Page 71
(2) Heat Exchanger Wiring
The starting interlock string (120VAC) connection from the
front heat exchanger on the ignition control is wired from
terminal 6 (J5 Boiler Start) to HeatNet control J16.2. This
connection ensures that the middle and rear heat exchangers
can‘t start unless the Manager starts.
The J5 Option connection on the Manager is wired to the
Main Valve signal on the rear exchanger. If a third heat
exchanger is present, the third (rear) heat exchanger’s Main
Valve is wired to the middle control’s J5 Option input (daisy
chain). This connection is to ensure that the Manager knows
that the other Heat exchangers have their main valves open.
This method performs as a redundant check of the minibus
state.
The Scanner Air Press input on J11B of the Manager is wired
to the Alarm contacts of J13B of the middle/rear (or first
subordinate boiler). If 3 heat exchangers are present, the last
subordinate or rear heat exchanger’s Alarm contacts are wired
to the Middle heat exchanger’s Scanner Air Press input (daisy
chain). This is to let the Manager know of a fault on the
subordinates and also provides a redundant check of an alarm
condition of the minibus state.
(3) Heat Exchanger wiring
Also, ensure that the termination switch S1 on the Minibus
board, is set as shown in the drawings. The end heat
exchangers have the switch down (ON) and the middle
exchanger has the S1 termination up (OFF).
MANAGER
SUBORDINATE
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MANAGER
SUBORDINATE
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SUBORDINATE
